1. Field of the Invention
The present invention is directed to new oxaspiroalkane ethers, their use as herbicides and to compositions thereof.
2. Summary of the Invention
The present invention is directed to novel compounds of formulas I or II ##STR2## wherein R is an optionally substituted unsaturated group containing up to 4 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, a secondary alkyl group containing 3 to 10 carbon atoms, an aromatic group containing up to 14 carbon atoms or a heterocyclic group containing up to 14 carbon atoms; in formula I, m is 0, 1 or 2; n is 1, 2 or 3; R.sup.1 and R.sup.2 each independently is a hydrogen atom, an alkyl group containing 1 to 6 carbon atoms, or a hydroxyalkyl or an alkoxymethyl group in which the alkyl portion contains 1 to 6 carbon atoms; X is CH.sub.2 when m is 0, 1 or 2 or X is oxygen when m is 1 or 2; or in formula II, n is 1, 2 or 3; m is 0 or 1; and R.sup.1 and R.sup.2 each independently is a hydrogen atom, an alkyl group containing 1 to 6 carbon atoms, or a hydroxyalkyl or an alkoxymethyl group in which the alkyl portion contains 1 to 6 carbon atoms. The compounds of formulas I and II are useful as plant growth regulators or herbicides.
In the compounds of formulas I or II, preferably R.sup.1 and R.sup.2 each independently is a hydrogen atom or a methyl or ethyl group. In one embodiment of the invention, R.sup.1 and R.sup.2 each is methyl group. Illustrative examples of such compounds include those species having the following structural features in formula I
______________________________________ m n X R.sup.1 R.sup.2 R ______________________________________ 1 3 CH.sub.2 CH.sub.3 CH.sub.3 2-chlorophenyl 1 3 CH.sub.2 CH.sub.3 CH.sub.3 2-methylphenyl 1 3 CH.sub.2 CH.sub.3 CH.sub.3 2-pyridinyl 2 2 CH.sub.2 CH.sub.3 CH.sub.3 2-fluorophenyl 2 2 CH.sub.2 CH.sub.3 CH.sub.3 2-chlorophenyl 2 2 CH.sub.2 CH.sub.3 CH.sub.3 2-methylphenyl 2 2 CH.sub.2 CH.sub.3 CH.sub.3 2-pyridinyl 2 1 0 CH.sub.3 CH.sub.3 2-fluorophenyl 2 1 0 CH.sub.3 CH.sub.3 2-chlorophenyl 2 1 0 CH.sub.3 CH.sub.3 2-methylphenyl 2 1 0 CH.sub.3 CH.sub.3 2-pyridinyl ______________________________________
In the compounds of formulas I or II, preferably R is an ethynyl group, a 2-pyridinyl group or a phenyl group optionally substituted by 1 or 2 chlorine or fluorine atoms or methyl group. In specific embodiments of the invention, R is a 2-chlorophenyl, a 2-fluorophenyl or a 2-methylphenyl group.
In the compounds of formula I, preferably m is 1 and n is 1 or 2, and for compounds of formula II, preferably m is 0 and n is 1 or 2. Illustrative examples of such compounds include those species having the following structural features
______________________________________ Formula I m n X R.sup.1 R.sup.2 R ______________________________________ 1 2 0 H H 2-chlorophenyl 1 2 0 H H 2-methylphenyl 1 2 0 H H 2-pyridinyl 1 2 CH.sub.2 H H 2-chlorophenyl 1 2 CH.sub.2 H H 2-methylphenyl 1 2 CH.sub.2 H H 2-pyridinyl 1 2 CH.sub.2 CH.sub.3 CH.sub.3 2-chlorophenyl 1 2 CH.sub.2 CH.sub.3 CH.sub.3 2-methylphenyl 1 2 CH.sub.2 CH.sub.3 CH.sub.3 2-pyridinyl 1 1 0 H H 2-chlorophenyl 1 1 0 H H 2-methylphenyl 1 1 0 H H 2-pyridinyl 1 1 CH.sub.2 H H 2-chlorophenyl 1 1 CH.sub.2 H H 2-methylphenyl 1 1 CH.sub.2 H H 2-pyridinyl 1 1 0 CH.sub.3 CH.sub.3 2-chlorophenyl 1 1 0 CH.sub.3 CH.sub.3 2-pyridinyl ______________________________________
______________________________________ Formula II m n X R.sup.1 R.sup.2 R ______________________________________ 0 2 -- CH.sub.3 CH.sub.3 2-chlorophenyl 0 2 -- CH.sub.3 CH.sub.3 2-methylphenyl 0 2 -- CH.sub.3 CH.sub.3 2-pyridinyl ______________________________________
In the compounds of formula I, X is preferably CH.sub.2.
The compounds of formulas I and II of the present invention can exist in several stereoisomeric forms, such as cis-configuration, trans-configuration, as well as in optically-active forms. These individual forms as well as mixtures thereof are within the scope of the compounds of formulas I and II of the present invention. The various isomers of the compounds of the invention may have different herbicidal or plant growth regulator properties and usually the compounds having the cis-configuration of the ether substituent to the oxygen atom of the heterocyclic ring have the highest biological activity. One may prefer to deliberately create mixtures or to resolve an isomer mixture to recover a more active isomer form or to prepare the more active form directly for use in the invention. The compounds of the invention also have utility as solvents or dispersing agents for pigments, paints, polymers and synthetic fibers.
Illustrative embodiments of the compounds of formula I of the invention include those species having the following structural features
______________________________________ m n X R.sup.1 R.sup.2 R ______________________________________ 1 3 0 H H 2-chlorophenyl 1 3 0 H H 2-methylphenyl 1 3 0 H H 2-pyridinyl 1 3 CH.sub.2 H H 2-chlorophenyl 1 3 CH.sub.2 H H 2-methylphenyl 1 3 CH.sub.2 H H 2,6-dichlorophenyl 1 3 CH.sub.2 H H 2-pyridinyl 1 3 CH.sub.2 H H 2-ethynyl 1 3 CH.sub.2 H H 2-pyrimidinyl 1 3 CH.sub.2 H H 4,6-dimethyl-1,3,5- triazin-2-yl 1 3 CH.sub.2 H H cyclopropyl 1 3 CH.sub.2 H H tetrahydro-2- pyranyl 2 3 0 H H 2-fluorophenyl 2 3 0 H H 2-chlorophenyl 2 3 0 H H 2-methylphenyl 2 3 0 H H 2-pyridinyl 2 3 CH.sub.2 H H 2-fluorophenyl 2 3 CH.sub.2 H H 2-chlorophenyl 2 3 CH.sub.2 H H 2-methylphenyl 2 3 CH.sub.2 H H 2-pyridinyl 2 3 CH.sub.2 CH.sub.3 CH.sub.3 2-fluorophenyl 2 3 CH.sub.2 CH.sub.3 CH.sub.3 2-chlorophenyl 2 3 CH.sub.2 CH.sub.3 CH.sub.3 2-methylphenyl 2 3 CH.sub.2 CH.sub.3 CH.sub.3 2-pyridinyl 2 2 0 H H 2-fluorophenyl 2 2 0 H H 2-chlorophenyl 2 2 0 H H 2-methylphenyl 2 2 0 H H 2-pyridinyl 2 2 CH.sub.2 H H 2-fluorophenyl 2 2 CH.sub.2 H H 2-chlorophenyl 2 2 CH.sub.2 H H 2-methylphenyl 2 2 CH.sub.2 H H 2-pyridinyl 2 1 0 H H 2-fluorophenyl 2 1 0 H H 2-chlorophenyl 2 1 0 H H 2-methylphenyl 2 1 0 H H 2-pyridinyl 2 1 CH.sub.2 H H 2-fluorophenyl 2 1 CH.sub.2 H H 2-chlorophenyl 2 1 CH.sub.2 H H 2-methylphenyl 2 1 CH.sub.2 H H 2-pyridinyl ______________________________________
The compounds of formula I of the invention wherein m is 0, 1 or 2 and X is CH.sub.2 are prepared from 2-RCH.sub.2 O-ether-substituted cycloalkanols III ##STR3## in which n is 1, 2 or 3 and R is an optionally substituted unsaturated group containing up to 4 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, a secondary alkyl group containing 3 to 10 carbon atoms, an aromatic group containing up to 14 carbon atoms or a heterocyclic group containing up to 14 carbon atoms, by oxidation to the corresponding ketone, reaction with the appropriate Grignard reagent to form the corresponding vinylic, allylic or homoallylic cyclohexanol ether followed by spirocyclization.
The oxidation of the substituted cycloalkanols is conducted by conventional techniques known in the art, for example, using (a) potassium dichromate in (sulfuric) acid in the presence of tetrabutylammonium bisulfate and methylene chloride, or (b) (COCl).sub.2, dimethyl sulfoxide and triethylamine in methylene chloride as taught by Swern et al, J. Org. Chem., 1978, 43(12), page 2480.
The ketone from the above oxidation was treated with the appropriate conventional Grignard reagent system to form the desired vinylic, allylic or homoallylic substituted cycloalkanol in the presence of anhydrous ethers, such as tetrahydrofuran, as taught by Still and McDonald, Tetrahedron Letters, 1980, 21, page 1031.
The vinylic, allylic or homoallylic substituted cycloalkanols are spirocyclized by application of conventional techniques known in the art, for example, (a) formation of a 1,3-, 1,4- or 1,5-diol, e.g. with diborane-tetrahydrofuran, sodium hydroxide and hydrogen peroxide followed by treatment with triphenylphosphine and diethyl diazoacetate; and the allylic or homoallylic substituted cycloalkanols are also spirocyclized by (b) acid catalyzed cyclization of a, 4- or 5-alken-1-ol, e.g. with aqueous p-toluenesulfonic acid in benzene at room temperature of (c) epoxidation-cyclization of a, 4- or 5-alken-1-ol, e.g. with m-chloroperbenzoic acid in methylene chloride.
The compounds of formula I of the invention wherein m is 1 or 2 and X is 0 are prepared from the ether-substituted cycloalkanols, III, by oxidation to the corresponding ketone as described above followed by treating the resulting ketone with the appropriate diol, e.g. ethylene glycol and a catalyst such as p-toluenesulfonic acid or the like.
The compounds of formula II of the invention are prepared by conventional techniques from the ether substituted cycloalkanols of formula III by first preparing the corresponding ketone as described above and by treating the ketone with a 3,3-dialkyl-3-(dimethyl-t-butylsilyloxy)propyne or butyne compound and an appropriate Grignard reagent system, e.g. alkylmagnesium chloride in tetrahydrofuran, hydrogenating the resulting product, e.g. with palladium on barium sulfate and quinoline, and cyclizing the resulting product, e.g. with tetraalkylammonium fluoride in tetrahydrofuran followed by aqueous p-toluenesulfonic acid in benzene, to give the desired compound of formula II.
The ether-substituted cycloalkanols of formula III are prepared by treating cycloalkanediols with a compound of the formula RCH.sub.2 X in which R is defined as in formula I or II above and X is a halogen atom, such as bromine, chlorine or iodine, or is a mesyloxy, tosyloxy group or the like, in the presence of a base and an inert diluent. The base is suitably an alkali metal hydride, hydroxide or carbonate, including, for example, sodium hydride, sodium hydroxide, potassium carbonate and the like. Inert diluents are suitably organic solvents, such as ethers, aromatic hydrocarbons, chlorinated hydrocarbons and the like, including, for example, diethyl ether, tetrahydrofuran, dimethyl sulfoxide, toluene, methylene chloride and the like. The reaction can be conducted in a two-phase system, preferably in the presence of a phase-transfer catalyst. For example, the system is aqueous sodium or potassium hydroxide solution with toluene or methylene chloride and the phase-transfer catalyst is an ammonium compound such as tetra-n-butylammonium chloride, bromide, or hydrogen sulfate, triethylbenzylammonium chloride or the like. The reaction is usually carried out under normal pressures and ambient temperatures. Suitable temperatures for the reaction are from about 0.degree. to about 120.degree. C., preferably from about 20.degree. to about 100.degree. C. The product ethers are recovered and isolated by conventional techniques. The cycloalkanediols, some of their ethers and their preparations are known as, for example, in U.S. Pat. No. 4,282,388.